The proposed research has two principal aims: First, to assess the effects of distance cues and visual context on perceived velocity, and second, to examine three mechanisms for the perceptual processing of velocity. The relative angular velocity model attributes perceived velocity to the processing of relative angular velocity, i.e., the proportion of a movement field traversed per unit of time. The phenomenal extent model proposes that perceived velocity is mediated by prior determination of the extent of the movement path. The distance calibration model suggests that perceived velocity is the output of a process by which absolute angular velocity is calibrated by registered distance.